Type V collagen modulates alloantigen-induced pathology and immunology in the lung.

Perivascular and peribronchiolar tissues are targets of the immune response during lung allograft rejection. Collagen type V (col[V]) is located within these tissues. Col(V) may be major histocompatibility complex (MHC)-like, and MHC-derived peptides have been used to induce immunologic tolerance and prevent rejection in allografts other than the lung. The current study tests the hypothesis that col(V) could be used to downregulate immune responses to lung alloantigen in vivo. We developed a murine model in which instillations of allogeneic bronchoalveolar lavage (BAL) cells (C57BL/6, I-a(b), H-2(b)) into lungs of BALB/c mice (I-a(d), H-2(d)) induce histology similar to grades 1 and 2 acute lung allograft rejection, apoptosis of airway epithelium and vascular endothelium, and upregulate tumor necrosis factor (TNF)-alpha production locally. The current study reports that instillations of col(V) into lungs before allogeneic BAL cells prevent development of rejection pathology and apoptosis, downregulate alloantigen-induced T-lymphocyte proliferation, and abrogate local TNF-alpha production. In addition, instillation of col(V)-pulsed autologous BAL cells into lungs of mice primed with allogeneic BAL cells perpetuates rejection pathology. Collectively, these data show that col(V) is a novel antigen involved in the rejection process, and suggest that col(V) could be used to modulate the rejection response to lung allografts.

Medical thoracoscopic talc pleurodesis for chylothorax due to lymphoma: a case series.

STUDY OBJECTIVES: Recurrent chylothorax as a complication of lymphoma has had unsatisfactory outcomes. Serial thoracentesis, tube thoracostomy, and pleurodesis via chest tube have been ineffective and compromise the nutritional and immune status of the patient. Medical thoracoscopic talc pleurodesis has been safe and effective in the treatment of some other varieties of recurrent pleural effusions. Our objective was to investigate the safety and efficacy of medical thoracoscopic talc pleurodesis in the palliation of chylothorax related to lymphoma. DESIGN: This is a report of 24 hemithoraces treated in 19 consecutive patients with lymphoma-related chylothorax, failing chemotherapy or radiation therapy. The average patient age was 55 years. INTERVENTIONS: Medical thoracoscopy was performed under local anesthesia and conscious sedation in a bronchoscopy suite. Sedation included midazolam (mean dose, 6 mg; range, 2-14 mg) with either meperidine (mean dose, 94 mg; range 25-140 mg), or morphine (mean dose, 18 mg; range 4-40 mg). Pleurodesis was performed with insufflation of sterile asbestos-free talc, (4-8 g). After pleurodesis, chest tubes were placed, with the mean duration of chest tube placement being 4 days, range 3 to 10 days. RESULTS: One patient died a few days after the procedure due to causes related to the primary disease process. Follow-up was for at least 90 days following the procedure. Patients were assessed at 30, 60, and 90 days following the procedure. At each of these endpoints, all patients remaining alive were without recurrence of pleural effusions, which was confirmed by chest radiography. Eight patients in the series died of the effects of their malignancy during the 90-day evaluation interval. Complications included medication reactions in two patients (8.3%) and ARDS in one patient (4.1%). CONCLUSION: Many patients with lymphoma-related chylothorax are refractory to chemotherapy and/or radiation therapy. In this group, medical thoracoscopic talc pleurodesis has an acceptable complication rate and a 100% success rate in the prevention of recurrence of pleural effusions at 30, 60, and 90 days following the procedure.

Bronchoscopy in the diagnosis of respiratory infections.

In recent years, several factors have altered the spectrum of respiratory infections and their likelihood of response to empiric treatment. Altered microbial resistance has led to the possible need for specific etiologic diagnosis in some hospital-acquired infections in the normal host. In the immune-compromised host, the spectrum of atypical presentations and unusual organisms limits the clinician's ability to choose effective empiric therapies. In the normal host, bronchoscopic diagnosis seems to be most useful in the groups with severe community-acquired pneumonia or poor response to therapy for community-acquired pneumonia. The group of patients with ventilator-associated pneumonia has been well-researched and the bronchoscopic techniques tend to show increased sensitivity over other diagnostic means, but this has not been proven to alter morbidity, mortality, or cost effectiveness. The immune-compromised host is commonly infected by organisms not easily diagnosed by other means and is thus unable to be treated empirically. Bronchoscopic diagnostic techniques play a larger and more clearly delineated role in these populations, including the patient populations with solid organ transplants, bone marrow transplants, and AIDS.